Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

International Journal of Modern Physics B

Optical properties of an exciton trapped by an ionized donor in ellipsoidal quantum dots under electric field and hydrostatic pressure

Lei Shi, Yan Zu-wei

Published May 7, 2019• 4 citations
Publisher

Abstract

The optical properties of an exciton trapped by an ionized donor in an ellipsoidal quantum dot (QD) with both oblate and prolate shapes under applied electric field and hydrostatic pressure have been studied. We have calculated the linear and third-order nonlinear absorption coefficients (ACs) and refractive index changes (RICs) by using a variational method within the perturbation theory. The results show that the QD shape and size have a significant influence on the positions and magnitudes of the peaks of the (ACs) and RICs, moreover, the influence of hydrostatic pressure and electric field under different QD shape is also different.

DOI
10.1142/s021797921950108x

Related papers

Non-linear optical properties of excitonic complexes in prolate ellipsoidal quantum dot

Yuri Y. Bleyan, Maxim Ya. Vinnichenko, Nabil Zeiri +2 more

This study presents a theoretical study of ground-state exciton and biexciton properties in strongly prolate ellipsoidal GaAs quantum dot. Using a variational approach with trial wave functions constructed from single-particle states, we examine the dependence of exciton and biexciton energies on the dot’s geometric parameters. The oscillator strengths of exciton–biexciton transitions are analyzed as functions of the major and minor semiaxes. We further investigate the third-order optical susceptibility near single- and two-photon resonances, elucidating the role of exciton–biexciton interactions. The results show that one-photon resonances dominate the nonlinear response, with contributions exceeding those of two-photon resonances by approximately four orders of magnitude. Absorption coefficients for exciton and biexciton transitions are evaluated for a fixed major semiaxis and varying minor semiaxis, along with the biexciton two-photon absorption coefficient. Finally, we analyze biexciton-induced nonlinear refractive index modulation, which exhibits a sign reversal across resonance and a pronounced peak–dip structure, indicating strong dispersive behavior and significant excitonic phase modulation.

Results in Optics•Feb 1, 2026•1 citation

Effects of the Magnetic Field on the Linear and Nonlinear Optical Absorption Coefficients and the Refractive Index Changes in a Spherical Quantum Dot

Muharrem Kırak, Sait Yılmaz, Mustafa Gençaslan

The linear and third-order nonlinear optical absorption coefficients (ACs) and the refractive index change (RIC) for a spherical quantum dot, having a hydrogenic impurity under an applied magnetic field have been theoretically studied. In numerical calculations, a variational scheme is adopted within effective mass approximation to determine the energy eigenvalues for the impurtiy. The variations of impurity binding energy with the dot radius, the linear and nonlinear ACs and RIC with the photon energy are investigated and effect of homogeneous magnetic field strength is discussed on these optical properties. It has been found that the binding energy, ACs and RIC are sensitively dependent on the magnetic field strength. Moreover, the calculated results also indicate that the absorption peak energies move to higher energies with increasing magnetic field.

Journal of Nanoelectronics and Optoelectronics•Dec 1, 2010•8 citations

INTERSUBBAND OPTICAL ABSORPTION COEFFICIENTS AND REFRACTIVE INDEX CHANGES OF AN ELLIPSOIDAL FINITE POTENTIAL QUANTUM DOT

G. Rezaei, M.R.K. Vahdani, M. Barati

Intersubband optical absorption coefficient and refractive index changes of a weakly prolate ellipsoidal quantum dot, using the compact-density matrix formalism and iterative method, are investigated. In this regard, the linear and nonlinear intersubband optical absorption coefficient and refractive index changes of a GaAs / Al x Ga 1-x As ellipsoidal quantum dot, as functions of the dot radius, ellipticity constant, stoichiometric ratio and incident light intensity are calculated. The results indicate that absorption coefficient and refractive index changes strongly depend on the light intensity, size and geometry of the dot and structure parameters such as aluminium concentration in GaAs / Al x Ga 1-x As structures.

Journal of Nonlinear Optical Physics & Materials•Mar 1, 2010•8 citations

External electric field effect on the nonlinear optical properties of a laser dressed donor impurity in a GaAs spherical quantum dot confined at the center of a Ga 1-x Al x As cylindrical nano-wire

Ghasem Safarpour, Mohammad Izadi, M. Novzari +1 more

Linear and third order nonlinear optical absorption coefficients and refractive index changes of an on-center donor impurity in a spherical GaAs quantum dot which is located at the center of a cylindrical Ga 1 -x Al x As nano-wire, have been investigated under the simultaneous effect of electric field and laser radiation. The linear and third order nonlinear optical properties are calculated based on optical 1-2, 2-3 and 1-3 transitions by means of the compact density-matrix approach. The energy eigenvalues and corresponding wave functions are calculated using finite difference approximation and reliability of calculated wave functions is checked by computing orthogonality. It is shown that optical spectrum shifts towards lower and higher energies for 1-2 transition and shifts towards lower energies for 2-3 and 1-3 transitions as the electric field strength increases. The presence of laser field shifts absorption spectrum towards lower energies. In the absence of electric and laser field, the magnitude of absorption coefficient and refractive index changes increase in transitions between higher levels. Simultaneous presence of both electric field and laser radiation has great effect on magnitude of absorption coefficients and refractive index changes. The saturation in optical spectrum can be adjusted by electric field and laser radiation.

Indian Journal of Pure & Applied Physics•Jan 5, 2015•6 citations

Electron-related nonlinear optical properties of cylindrical quantum dot with the Rosen–Morse axial potential

Fatih Ungan, Mustafa Kemal Bahar, Suvajit Pal +1 more

Abstract We present a theoretical study on the effects of intense laser field (ILF) and static electric field on the linear and nonlinear optical properties of a cylindrical quantum dot with Rosen–Morse axial potential under the framework of effective mass and parabolic band approximations. This study also takes into account the effects of the structure parameters ( η , V 1 , and R ). The analytical expressions of the linear, third-order nonlinear and total optical absorption coefficients (TOACs) and the relative refractive index changes (RRICs) are obtained by using the compact-density-matrix approach. The results of numerical calculations show that the resonant peak position of the TOACs and RRICs shifts towards lower energies and the magnitude of the peak increases with the effect of the static electric field and ILF. In addition, it is observed that while the resonant energies of the TOACs and RRICs of system shift towards the higher (lower) energies with the enhancement of η , V 1 , they decrease with the augmentation of R . Thus, the findings of this study show that the optical properties of the structure can be adjusted by changing the magnitude of structure parameters and applied external fields.

Communications in Theoretical Physics•Jun 24, 2020•18 citations

Investigation of Biexciton Induced Linear and Nonlinear Refractive Index Changes in Ellipsoidal Quantum Dot

Yuri Y. Bleyan

Abstract The biexciton states of the ground and excited levels in a GaAs strongly oblate ellipsoidal quantum dot are studied with the use of the variational method. The trial variational wave function of the biexciton is constructed on single-particle wave functions, obtained within the geometrical adiabatic approximation. The biexciton energies are obtained from the geometric parameters of an ellipsoidal quantum dot for both the ground and excited states. The linear and nonlinear refractive indexes of the biexciton around one- and two-photon resonances are calculated as the real parts of the first- and third-order nonlinear susceptibilities, respectively. The spectra of changes of the biexciton refractive index for transitions between ground states as a function of the photon energy are obtained for different values of the small semiaxis of the ellipsoidal quantum dot.

Journal of Contemporary Physics (Armenian Academy of Sciences)•Dec 1, 2022•1 citation
The optical properties of an exciton trapped by an ionized donor in an ellipsoidal quantum dot (QD) with both oblate and prolate shapes under applied electric field and hydrostatic pressure have been studied. We have calculated the linear and third-order nonlinear absorption coefficients (ACs) and refractive index changes (RICs) by using a variational method within the perturbation theory. The results show that the QD shape and size have a significant influence on the positions and magnitudes of the peaks of the (ACs) and RICs, moreover, the influence of hydrostatic pressure and electric field under different QD shape is also different.
This study presents a theoretical study of ground-state exciton and biexciton properties in strongly prolate ellipsoidal GaAs quantum dot. Using a variational approach with trial wave functions constructed from single-particle states, we examine the dependence of exciton and biexciton energies on the dot’s geometric parameters. The oscillator strengths of exciton–biexciton transitions are analyzed as functions of the major and minor semiaxes. We further investigate the third-order optical susceptibility near single- and two-photon resonances, elucidating the role of exciton–biexciton interactions. The results show that one-photon resonances dominate the nonlinear response, with contributions exceeding those of two-photon resonances by approximately four orders of magnitude. Absorption coefficients for exciton and biexciton transitions are evaluated for a fixed major semiaxis and varying minor semiaxis, along with the biexciton two-photon absorption coefficient. Finally, we analyze biexciton-induced nonlinear refractive index modulation, which exhibits a sign reversal across resonance and a pronounced peak–dip structure, indicating strong dispersive behavior and significant excitonic phase modulation.
The linear and third-order nonlinear optical absorption coefficients (ACs) and the refractive index change (RIC) for a spherical quantum dot, having a hydrogenic impurity under an applied magnetic field have been theoretically studied. In numerical calculations, a variational scheme is adopted within effective mass approximation to determine the energy eigenvalues for the impurtiy. The variations of impurity binding energy with the dot radius, the linear and nonlinear ACs and RIC with the photon energy are investigated and effect of homogeneous magnetic field strength is discussed on these optical properties. It has been found that the binding energy, ACs and RIC are sensitively dependent on the magnetic field strength. Moreover, the calculated results also indicate that the absorption peak energies move to higher energies with increasing magnetic field.
Intersubband optical absorption coefficient and refractive index changes of a weakly prolate ellipsoidal quantum dot, using the compact-density matrix formalism and iterative method, are investigated. In this regard, the linear and nonlinear intersubband optical absorption coefficient and refractive index changes of a GaAs / Al x Ga 1-x As ellipsoidal quantum dot, as functions of the dot radius, ellipticity constant, stoichiometric ratio and incident light intensity are calculated. The results indicate that absorption coefficient and refractive index changes strongly depend on the light intensity, size and geometry of the dot and structure parameters such as aluminium concentration in GaAs / Al x Ga 1-x As structures.
Linear and third order nonlinear optical absorption coefficients and refractive index changes of an on-center donor impurity in a spherical GaAs quantum dot which is located at the center of a cylindrical Ga 1 -x Al x As nano-wire, have been investigated under the simultaneous effect of electric field and laser radiation. The linear and third order nonlinear optical properties are calculated based on optical 1-2, 2-3 and 1-3 transitions by means of the compact density-matrix approach. The energy eigenvalues and corresponding wave functions are calculated using finite difference approximation and reliability of calculated wave functions is checked by computing orthogonality. It is shown that optical spectrum shifts towards lower and higher energies for 1-2 transition and shifts towards lower energies for 2-3 and 1-3 transitions as the electric field strength increases. The presence of laser field shifts absorption spectrum towards lower energies. In the absence of electric and laser field, the magnitude of absorption coefficient and refractive index changes increase in transitions between higher levels. Simultaneous presence of both electric field and laser radiation has great effect on magnitude of absorption coefficients and refractive index changes. The saturation in optical spectrum can be adjusted by electric field and laser radiation.
Abstract We present a theoretical study on the effects of intense laser field (ILF) and static electric field on the linear and nonlinear optical properties of a cylindrical quantum dot with Rosen–Morse axial potential under the framework of effective mass and parabolic band approximations. This study also takes into account the effects of the structure parameters ( η , V 1 , and R ). The analytical expressions of the linear, third-order nonlinear and total optical absorption coefficients (TOACs) and the relative refractive index changes (RRICs) are obtained by using the compact-density-matrix approach. The results of numerical calculations show that the resonant peak position of the TOACs and RRICs shifts towards lower energies and the magnitude of the peak increases with the effect of the static electric field and ILF. In addition, it is observed that while the resonant energies of the TOACs and RRICs of system shift towards the higher (lower) energies with the enhancement of η , V 1 , they decrease with the augmentation of R . Thus, the findings of this study show that the optical properties of the structure can be adjusted by changing the magnitude of structure parameters and applied external fields.
Abstract The biexciton states of the ground and excited levels in a GaAs strongly oblate ellipsoidal quantum dot are studied with the use of the variational method. The trial variational wave function of the biexciton is constructed on single-particle wave functions, obtained within the geometrical adiabatic approximation. The biexciton energies are obtained from the geometric parameters of an ellipsoidal quantum dot for both the ground and excited states. The linear and nonlinear refractive indexes of the biexciton around one- and two-photon resonances are calculated as the real parts of the first- and third-order nonlinear susceptibilities, respectively. The spectra of changes of the biexciton refractive index for transitions between ground states as a function of the photon energy are obtained for different values of the small semiaxis of the ellipsoidal quantum dot.